Elastic surgical stocking



Nov. 20, 1962 w. H. BIRD 3,064,456

ELASTIC SURGICAL STOCKING Filed Nov. 29, 1957 2 Sheets-Sheet l INVENTOR Mm? fiw/Fr 5/50- ATTORNEY Nov. 20, 1962 w. H. BIRD 3,064,456

ELASTIC SURGICAL s'rocxmc Filed Nov. 29, 1957 2 Sheets-Sheet 2 INVENTOR WAC/(4M 647W) 67/90 44,; r MW ATTORNEY i to The present invention relates to improved elastic surgical stockings and to methods of making the same. More specifically, the present invention is concerned with improved elastic surgical stockings which are capable of exerting the required restricting and compressive force on the leg of the wearer over extended periods of use.

Elastic surgical stockings have been made in the past and many of these stockings have found considerable commercial success in the industry. When these stockings are placed on the legs of the wearer requiring support because of physical or pathological conditions, immediate relief is usually afiiorded to some degree due to the restricting or compressive force exerted on the legs by the elastic surgical stockings.

Unfortunately, some of these stockings, and particularly those containing synthetic thermoplastic yarns, such as nylon, even if properly fitted and correctly proportioned at the outset, tend to become wrinkled, loose and baggy during wear because of the usual ileidng and bending of the stocking at the knee and the ankle during walking, sitting, kneeling, and other physical activities. This is true especially in the case or" circular-knit stockings which are not fully fashioned to conform to the shape of the leg and, to a lesser extent, in the case of full-fashioned stockings which conform more closely to the shape of the leg.

When these wrinkles, looseness and bagginess develop, the wearer usually seeks to make adjustments therefor by pulling the top or thigh portion of the stocking up wardly to stretch it in the lengthwise direction and then anchoring it in this higher position by having the usual garter or girdle connections or other fasteners reach down to lower anchoring points on the stocking welt. This will usually take care of the wrinkles, looseness and bagginess at knee and upper calr" areas. in some cases, this has also afforded some temporary or partial removal of the wrinkles, looseness and bagginess at the ankle area of the stockings but, in other cases, it has not improved the situution at the ankle area at all. In these latter cases, con tinued pulling'and stretching upwardly has merely intro duced the possibility of ripping or tearing the stocking before the wrinkles, looseness and bagginess are removed from the ankle area. Additionally, continued pullin up wardly of the stocking tends to increase the compressive force on the higher portions of stocking to a point wherein the free circulation and flow of blood is restricted.

This situation is all the more serious when it is realized that the restricting and compressive force of the stocking is most seriously needed at the ankle area. Thus, the elastic stockings become not only wrinkled, loose, unsightly and ill-appearing after a relatively short period of use but also become relatively inefficient and ineifectual in the most critically needed ankle area.

it is believed that the difficulties of removing the wrinkles, looseness and bagginess at the ankle areas is clue primarily to the fact that such areas are removed a greater distance from the anchorage points near the tops of the stockings and thus require greater stocking-stretching forces. Added to this is the fact that upward movement of the stocking at the ankle area requires circumferential expansion of the stocking in order for it to actually move upwardly into the lower calf area which normally possesses greater girth than the ankle area and consequently resists such upward movement.

Eatented Nov. 20, 1952 It has now been found that the wrinkles, looseness and 'bagginess may be avoided in the ankle and lower. calf area by means of an improved stocking construction of the present invention.

More specifically, it has now been found that the pre viously mentioned disadvantages and defects of prior art stockings may be avoided by knitting (1) the upper portion of the stocking which normally comprises the thigh, the mid-thigh, knee, upper calf areas with a balanced construction of alternating courses of (a) right-twist-teudency synthetic thermoplastic yarns containing from one to four monofilaments and (b) left-twist-tendency synthetic thermoplastic yarns containing from one to four monofilaments, and then knitting (2) the lower portion of the stocking which normally comprises the lower calf, ankle and foot areas with a balanced construction of alternating courses of textile yarns of which at least one course is a rubber or an elastomeric yarn having an initial elastic stretch of from about to about 600 percent of its original unstretched length andthe capability of returning substantially instantaneously to its original unstretched length after being so stretched.

The word monofilament is not used in its narrow restricted sense to cover only synthetic filaments containing a sin le heavy strand but is intended to cover yarns containing from one to about four strands of monofilamerits, each of suificient size as to be capable of functioning as a yarn in normal textile operations. This conforms with A.S.T.lvl. definition stating: Monofilamenta single filament of suiIicient size to function as a yarn in normal textile operations. 55.

The term right-twist-tendency and leit-twist-tendency yarns is intended to describe those yarns which were twisted originally during their manufacture and acquired a more or lms permanent set in that twisted state but which have become untwisted to some degree from that twisted state and hence possess a tendency to return thereto. In other and more specific words, a yarn which, for example, received 20 right twists per inch during its manufacture had become more or less permanently set in that 20 right twists per inch condition, and which was then untwisted so that it had less than 20 right twists, or no twist, or even a left twist, would be considered a right-twist-tendency yarn inasmuch as it possesses a strong tendency to revert to its prior 20 right twist condition.

It is to be observed in passing that this tendency to revert to the original set twisted condition is accompanied by a corresponding tendency to shorten in over-all length whereby these twist-tendency yarns, when knitted into an elastic surgical stocking, tend to shorten in length and thus impose restricting and compressive forces on the legs within the stockings. The exertion of these forces is a teature of the present invention and the use thereof will become clearer from the further discussion of the inventive concept.

The lower portion of the elastic surgical stocking which normally comprises the lower calf, ankle and foot areas thereof is knitted of a balanced construction of alternating courses of textile yarns of which at least one course is a rubber or elastomeric yarn having an elastic stretch of from about 150 to about 660 percent of its original unstretched length and the capability of returning substantially instantaneously to its original unstretched length after being so stretched.

Such a construction in the lower portion of the stocking avoids the development of wrinkles, looseness and bagginess in the ankle area whereby the necessity of pulling the stocking upwardly by the wearer is obviated completely. At the same time, sufiicient restricting and com- A.S.T.M. designation-z D-l23'- aoeaesc 3 pressive force is present to afiord support and relief to such wearers suffering from physical and pathological conditions such as varicose veins.

In some instances, the upper portion and the lower portion do not blend together well and a visible joint is created at the line where they meet. This is due primarily to the fact that the rubber yarns used in the lower portion normally are heavier and have a' larger diameter than the right and left-twist-tendency yarns normally used in the upper portion of the stocking. In such a case, it is preferable that a camouflage yarn be used in conjunction with the rightand left-twist-tendency yarns to match or balance the bulk appearance of the rubber yarn so that both upper and lower portion present are blended visually tothe same appearance, thereby avoiding the creation of a visible joint or line of junction of the two portions. This, of course, is almost a necessity when the stockings are worn in view of the general public but are not necessary when the stockings are worn under other garments'or in privacy.

With reference to the drawings:

FIGURE 1 is a schematic showing of one form of an elastic surgical stocking embodying the present inventive concept;

FIGURE 2 is an enlarged detail view of the knitted construction of the stocking in the upper portion thereof;

FIGURE 3 is an enlarged detail view of the knitted 7 construction of the stocking in the lower portion thereof;

FIGURE 4 is a schematic drawing of a full-length leotard elastic surgical stocking embodying the present inventive concept;

FIGURE 5 is a schematic drawing of a knee-high elastic surgical stocking embodying the present inventive concept; and

FIGURE 6 is a schematic drawing of a half-hose elastic surgical stocking embodying the present inventive concept.

In FIGURE 1, a stocking 1:) is shown comprising a welt 12, an after-welt 14, a mid-thigh portion 13, a knee portion 15, an upper calf portion 16, a lower calf portion 17, an ankle portion 18, a heel 20, a foot 22, and a toe or toecap 24. Narrowing marks 26 will, of course, be present 7 if the stocking is full-fashioned.

The welt 12, the after-welt 14, the heel 20 and the toe 24 are knitted in the usual manner known to the art and no further description thereof is believed required.

A full length leotard elastic surgical stocking is shown in FIGURE 4 and is basically similar in construction to the surgical stocking 10 illustrated in FIGURE 1 except struction is basically the same as the regular surgical stocking shown in FIGURE 1 except that there is no knee portion therein and that an elastic portion 19 is prefer-ably provided to hold the knee-high stocking in place below the knee.

An elastic surgical stocking of the half-hose type is shown in FIGURE 6 and is basically similar to the construction shown in FIGURE 5 except that the upper calf portion 16 therein is shorter and that an elastic portion 21 is preferably provided to hold the half-hose in place on the calf.

The invention will be further described with particular reference to the leotard full length stocking of FIGURE 4 but it is to be appreciated that such stocking has been selected merely because it basically possesses all the required portions of the stocking constructions shown. Such selection is made primarily for illustrative purposes and is not to be construed as limitative of the inventive concept.

The complete thigh portion 11, the knee portion 15 and the upper calf portion 16 are knitted of a balanced construction of alternating courses of right-twist-tendencysynthetic thermoplastic yarns 2 28 and left-twist-tendency synthetic thermoplastic yarn 3i 3%. This is shown in FIGURE 2 which illustrates a preferred embodiment of the inventive concept. The right-twist-tendency yarns 28, 23 are composite yarns and contain (1) a right twisttendency synthetic thermoplastic yarn 28a and (2) a crinkled, set thermoplastic synthetic yarn 281), which functions as a camouflage or blending yarn.

The right-twist-tendency synthetic thermoplastic yarn 28a forming the first component of the composite yarn 28 is preferably a lto 4-strand monofilament which has been so made and is so knitted as to possess the requisite right-twist-tendency. Substantially any synthetic thermoplastic yarn may be employed for the yarn 28, provided it can develop the required right-twist-tendency characteristics. Within the more commercial aspects of the present invention, nylon polyamide and Dacron polyester filaments, or equivalents thereof, have been found preferable.

The crinkled, set synthetic thermoplastic yarn 28b which forms the second component of composite yarn 28' is inserted for camouflage or blending purposes and may be any yarn having such crinkled, set properties but'is preferably of the nylon polyamide type or the Dacron polyester type, or equivalents thereof which has been crinkled and set preferably by the Helanca process disclosed in US. Patents 2,019,183; 2,019,185; 2,564,245 and 2,585,518. a

The right-twist-tendency synthetic thermoplastic yarn 28a and the crinkled, set synthetic thermoplastic camouflage yarn 28b which comprise the composite yarn ,28 are laid in the same course in the stocking by one yarn carrier of the usual type known to the art. These yarns are so laid in that course that they lie in side by side, substantially parallel relationship, as shown in FIGURE 2. This may be accomplished by drawing the right-twisttendency synthetic thermoplastic yarn .2811 and the crinkled, set synthetic, thermoplastic yarn 28b from separate supply-cones and joining them by means of suitableapparatus known to the art in parallel relationship in the yarn carrier which brings them to the knitting elements. If desired, the two yarns may be coned together prior to knitting whereby they will come from one cone and carried together in substantially parallel relationship to the knitting elements;

The right-twist-tendency characteristic by using yarns which were originally right twisted and which were more or less permanently set in that condition. Some degree of right-twist-tendency may be developed merely by originally winding the cone in such a direction that the drawing of the yarn during knitting from the end of the cone untwists the yarn one twist for each complete turn drawn from the cone. Increased twist tendency can be obtained by originally twisting the yarn highly, setting the yarn in that highly twisted state, then partially or completely removing the high twist and coning the yarn in the untwisted state under tension. The yarn embodiment of the invention, substantially all the twist is removed so that the twist-tendency yarns are practically twistless and the individual strands thereof are substantially parallel to each other in the final knitted product.

The left-twist-tendency yarns 3t 30 are prepared,

is developed 7 ose-nee twisted, coned and knitted in the same general fashion as the right-twist-tendency yarns, although naturally of opposite hand and opposite twist. Twist-tendency synthetic thermoplastic yarns 30a are used which possess a left-twist-tendency characteristic. These yarns 30a may also be used with crinkled, set synthetic thermoplastic camouflage yarns 39b and, if they are so used, the yarns 39a and 3% also may come from separate cones and are laid in together simultaneously in substantially parallel elationship in a single course by a second yarn carrier. Again, if desired, these yarns may be coned together in substantially parallel relationship prior to knitting and come from one cone to the knitting elements.

It is to be noted that the right-twist tendency yarns and the left-twist-tendency yarns, in adidtion to their tendency to shorten and exert restricting and compressive forces on the leg of the wearer, exert an opposing force on each other which opposes and pulls against the other yarn and thereby tends to increase synergistically the restricting and compressive force above the numerical sum of the restricting and compressive force of each one individually.

The thigh, mid-thigh, knee and upper calf portions 11, 13, and 16 are knitted in this balanced alternating course construction to the point at which it is desired to start the lower portion of the stocking containing a different course construction. The lower calf portion 17 usually marks the beginning of the lower portion and its position will vary depending upon the style, fashioning and general construction of the stocking 1 In most cases, however, it may be assumed to end at the middle or the lower end of the narrowing marks 26 shown in FIGURE 4.

The twist tendency yarn used in the manufacture of the thigh, knee and upper calf portion normally has a total denier in the range of from about 15 to about 4-0, with lower deniers than 15 being of use where increased Sheerness is desired and with higher deniers than 40 being or" use where heavier service weights are to be made. From 1 to about 4 strands of monofilaments may be used, with the individual denier of each monofilament ranging from about 4 to about 30.

In the thigh, knee and upper calf portions, the crinkled, set thermoplastic synthetic yarn 38b normally has a denier in the range of from about 20 to about 40, with lower deniers than 20* being capable of use where lighter stockings of greater sheerness are desired and with higher deniers than 40 being capable of use where heavier stockings of greater service are required.

It is not necessary that the crinkled, set synthetic thermoplastic yarns be used at all and, if they are used, it is not necessary that they be used in every course. They may be used in alternation in predetermined courses, as desired. it is also to be noted that more than one crinkled, set synthetic thermoplastic yarn may be used in a course and up to about three are so utilizable. As described previously, the primary function of these yarns is as camouflage or blending yarns to hide or obscure the line or junction created when shifting from one combination of course constructions to another.

The total denier of the composite yarn in the thigh, knee and upper calf portions therefore ranges from as low as about to as high as about 208 or more and the selection of a particular total denier will depend upon the weight of stocking desired, upon the yarns used in the lower portions of the stockings, upon the gauge of the knitting machine used and upon the ability of the knitting elements thereof to handle the yarns.

When the thigh, knee and upper calf portions have been completed, the two yarn carriers containing the right-twist-tendency yarn and the left-twist-tendency yarn become inoperative and other yarn carriers begin knitting the lower calf portion 17, the ankle portion 1% and the foot portion 22.

As shown FlGURE 3, the lower calf, ankle and foot portions li 18, 22 are knitted of a balanced construction of alternating courses of textile yarns of which at least one or all are elastic, stretchable yarns 38, such as rubber or elastoineric yarns having an initial elastic stretch of from about 150 to about 600 percent of its original unstretched length and capable of quick elastic recovery with a minimum of permanent deformation. The yarn 46 used in the balanced alternating course construction with the rubber or elastomeric yarn 33 may be a similar rubber or elastomeric yarn or it may be a synthetic yarn such as a crinkled, set nylon polyamide or Dacron polyester, cellulose acetate, regenerated cellulose, vinyl or acrylic fibers, polyethylene fibers, or natural fibers such as cotton, silk or wool. The course construction used in the lower calf portion 17 and ankle portion 18 extends from the lower end of the upper calf portion 16 to at least the heel 2d and preferably all the way through the foot portion 22 to the beginning of the toe or toe cap 2%.

The elastic s retchable yarns 38 included in the ankle and lower cal-f portion 13 (which may also include the foot portion 22) are preferably natural rubber threads but may be any synthetic or elastomeric yarn having similar stretching capacity (l5()*606'% of original unstretched length prior to covering) and the other properties and characteristic of rubber required for the present use.

The size or gauge of such elastic stretchable yarn is that equivalent t a guage size for rubber yarns of from about to about for a service weigh. tocking and from about to about 253 for a sheer stocking. These rubber yarns are usually helically wound or wrapped by one, two or more relatively inelastic yarns such as nylon, cotton, silk and the like having a weight equivalent to a denier of about 1G, 2G or 30. A coated rubber yarn may be used in lieu of the helically wound rubber yarn. The total denier of the wrapped or coated yarn is in the range of from about 65 to about 300.

The yarn 4d which is used in alternation with the rubber or elastomeric yarn may be another rubber or elastomeric yarn or" the same weight or may be a natural or synthetic yarn having a weight equivalent to a denier in the range of from about 20 to about 76 for a sheer stocking and from about 100 to about 309 for a service weight stocking. The synthetic yarns so used may be monoiilamerits or multifilaments, as desired.

Inasmuch as the elastic stretchable yarns 38 possess considerable restricting and com ressive force by themselves, it is not necessary that any twist-tendencies be developed in the yarns present in the ankle portion. These yarns may therefore be twisted to any desired degree or be twistless, if so desired.

The invention will he further illustrated in greater detail by the following specific examples. It should be understood, however, that although these examples may describe in particular detail some of the more specific features of the invention, they are given primarily for purposes of illustration and the invention in its broader aspects is not t be construed as limited thereto.

Example 1 An elastic surgical stocking such as illustrated in PEG- URE 1 is made on a standard 51-gauge knitting machine to illustrate the invention. The welt is made of 80 denier regular sylon. The after-welt is also made of 80 denier regular nylon and is knitted with the usual anti-run back or run-stop feature. The knee and upper calf areas are knitted of balanced alternating courses of (1) righttwist-tendency synthetic thermoplastic yarns of 4-strand 20 denier nylon monofilament polyamide yarns and 30 denier crinkled, set nylon polyamide Helanca multifiiamerit yarns, and (2) left-twist-tendency synthetic thermoplastic yarns of 4-strand 2O denier nylon monofiiament polyamide yarns and 39 denier crinkled, set nylon polyarnide Helanca multifilarnent yarns. In the knitting of all these yarns, the original twisting, coning and drawing from the cone is such that the yarns are substantially 7 twistless in the completed stocking and are substantially parallel to each other in each course.

At the end of knee and upper calf portions and just after the end of the narrowing operation, the lower calf, ankle and foot portions are then knitted of balanced alternating courses of (l) 160 gauge rubber yarns wrapped with one right-twist 20 denier nylon regular yarn and one left-twist 20 denier nylon regular yarn and (2) 60 denier nylon polyarnide regular monofilament yarns.

The stocking blank is then inspected, looped, seamed and completed in the usual manner known to the art. The resulting full-fashioned elastic surgical stocking is satisfactory and acceptable to the industry and afiords relief to those suffering from pathological conditions of the circulatory system such as varicose veins.

Example 2 V The procedures set forth in Example 1 are followed substantially as set forth therein with the exception that the knee and upper calf areas are knitted in alternating courses of two right-twist-tendency composite yarns and two left-twist-tendency composite yarns. The resulting stocking is comparable to the stocking of Example 1 Example 3 The procedures set forth in Example 1 are followed substantially as set forth therein with the exception that, in the ankle and lower calf areas, an 80 denier nylon polyamide multifilament yarn is used rather than the 60 denier monofilament yarns. The resulting stocking is comparable to the stocking of Example 1.

It is also to be noted that, although the balanced alternating course construction for the upper and lower portions of the stocking is illustrated and described primarily with reference to .a one-and-one alternating construction of the two different yarns, such is not to be construed as limitative of the present inventive concept. Other constructions, such as two-and-two or three-andthree alternations or various other balanced combinations, for example, may be used provided the resulting fabric possesses a stable, balanced, relatively curl-or-'kink-fIee nature.

Although several specific examples of the inventive concept have been described, the same should not be construed as limited thereby nor to the specific constructions and materials mentioned therein but to include various other equivalent constructions and materials as set forth in the claimsap ended hereto. It is understood that any suitable changes, modifications and variations may be made without departing from the spirit and scope of the invention.

-I claim:,

in an elastic stocking, an upper calf portion and a lower calf and ankle portion, said upper calf portion having a balanced construction of alternating courses of (a) right-twist-tendency synthetic thermoplastic yarns containing from one to four monofilaments and (b) lefttwist-tendency synthetic thermoplastic yarns containing 7 i from one to four monofilaments, and said lower calf and ankle portion having a balanced construction of alternating courses of yarns of which at least one of the alternat ing courses is an elastic yarn having a stretch capacity of from 150 to 600 percent of its original unstretched length and capable of returning substantially intantane-V ously to its original unstretched length after being so stretched, whereby, when said stocking is on the leg of a wearer, said lower calf and ankle portion exerts a sub- 7 stantially greater restraining pressure on the portion of fiage yarn and (b) left-twist-tendency synthetic thermoplastic yarns containing from one to four monofilaments and a camouflage yarn, and said lower calf and ankle portion having a balanced construction of alternating courses of yarns of which at least one of the alternating courses is an elastic yarn having a stretch capacity of from to 600 percent of its original unstretched length and capable of returning substantially instantaneously to its original unstretched length after being so stretched, whereby, when said stocking is on the leg of a wearer, said lower calf and ankle portion exerts a substantially greater restraining pressure on the portion of the Wearers leg covered thereby than the restraining pressure exerted by said upper calf portion.

3. An elastic surgical stocking as defined in claim 1 wherein the synthetic thermoplastic yarns are nylon.

4. An elastic surgical stocking as defined in claim 1 wherein the elastic yarn is rubber.

5. An elastic surgical stocking as defined in claim 1 wherein said stocking is of sutficient length to extend over the knee of a wearer and in which the construction of said stocking from the knee thereof down to and in cluding the upper calf portion thereof is the same, said like constructed portion exerting a restraining pressure when said stocking is worn that is substantially less. than the restraining pressure exerted by the lower calf and ankle portion of said stocking.

6. An elastic surgical stocking as defined in claim 1 wherein said stocking is of sufiicient length to extend over the knee and a substantial portion of the thigh of a wearer and in which the construction of said stocking from at least a portion of the thigh down to and including the upper calf portion thereof is the same, said like constructed portion exerting a restraining pressure when said stocking is worn that is substantially less than the restraining pressure exerted by the lower calf and ankle portion of said stocking. V

7. An elastic surgical stocking as defined in claim 1 wherein the foot of the stocking, with the exception of the toe and heel, has the same knitted construction as the lower calf and ankle portion and wherein said foot, ankle and lower calf portion exert substantially more restraining pressure, when said stocking is worn, than the remainder of said stocking.

8. In an elastic surgical stocking containing an upper leg portion including the section adapted to fit over the upper calf areas of a wearers leg and a' lower leg portion including the section adapted to fit around the ankle and areas adjacent thereto, the improvement comprising (1) said upper portion having a balanced construction of alternating courses of (a) right-twist-tendency synthetic thermoplastic yarns containing from one to four monofilaments and a crinkled, set thermoplastic synthetic yarn and (b) left-twist-tendency synthetic thermoplastic yarns containing from one to'four monofilaments and a crinkled, set thermoplastic synthetic yarn, and (2) a lower portion having a balanced construction of alternating courses of yarns of which at least one of the alternating courses is an elastic yarn having a stretch capacity of from about 150 to about 600 percentof its original unstretched length and capable of returning substantially instantaneously to its original unstretched length after being so stretched, whereby when said stocking is worn a substantially greater restraining pressure is exerted oh the lower calf and ankle of the wearer than on the upper part of the wearers leg beginning with the upper calf portion.

9. In an elastic surgical stocking containing an upper leg portion including the section adapted to fit over the upper calf areas of a wearers leg and a lower leg portion including the section adapted to fit around the ankle and areas adjacent thereto, the improvement comprising (1) said upper portion having a balanced construction of alternating courses of (a) right-twist-tendency synthetic thermoplastic yarns containing from one to four 1 monofilaments and a crinkled, set thermoplastic synthetic yarn and (b) left-twist-tendency synthetic thermoplastic yarns containing from one to four monofilaments and a crinkled, set thermoplastic synthetic yarn, and (2) a lower portion having a balanced construction of alternating courses of (a) elastic yarns having a stretch capacity of from about 150 to about 600 percent of their original unstretched length and capable of returning substantially instantaneously to its original unstretched length after being so stretched and (b) thermoplastic synthetic polymeric yarns, whereby when said stocking is worn a substantially greater restraining pressure is exerted on the lower calf and ankle of the wearer than on the upper part of the wearers leg beginning with the upper calf portion.

10. In an elastic surgical stocking containing an upper leg portion including the section adapted to fit over the upper calf areas of a wearers leg and a lower leg portion including the section adapted to fit around the ankle and areas adjacent thereto, the improvement comprising (1) said upper portion having a balanced construction of alternating courses of (a) right-twist-tendency synthetic thermoplastic nylon yarns containing from one to four monofilarnents and a crinkled, set thermoplastic synthetic yarn and (b) left-twist-tendency synthetic thermoplastic nylon yarns containing from one to four monofilaments and a crinkled, set thermoplastic synthetic yarn, and (2) a lower portion having a balanced construction of alternating courses of (a) elastic rubber yarns having a stretch capacity of from about 150 to about 600 percent of their original unstretched length and capable of returning substantially instantaneously to its original unstretched length 10 after being so stretched and (b) thermoplastic synthetic polyamide yarns, whereby when said stocking is Worn a substantially greater restraining pressure is exerted on the lower calf and ankle of the wearer than on the upper part of the wearers leg beginning with the upper calf portion.

11. In an elastic surgical stocking containing an upper leg portion including the section adapted to fit over the upper calf areas of a wearers leg and a lower leg portion including the section adapted to fit around the ankle and areas adjacent thereto, the improvement which comprises the lower leg portion having a substantially greater elastic stretch capacity than the elastic stretch capacity of the upper leg portion said stocking, when placed on a Wearers leg, exerting a substantially greater restraining pressure on the ankle and lower calf area of the Wearers leg than on the upper portion of the wearers leg including the upper calf portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,822,847 Adamson Sept. 8, 1931 2,169,203 Hinchliff Aug. 8, 1939 2,218,413 Bell Oct. 15, 1940 2,702,998 Purcell Mar. 1, 1955 2,714,757 Leath et al Aug. 9, 1955 2,720,097 De Mond Oct. 11, 1955 2,736,945 Burleson et al. Mar. 6, 1956 2,771,758 Weller Nov. 27, 1956 2,807,073 Stuewer Sept. 24, 1957 2,841,971 Bird et al. July 8, 1958 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,064 456 November 20, 1962 William Henry Bird It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below Column 4, line 30, strike out "'Helanca' Signed and sealed this 7th day of January 1964.

(SEAL) EDWIN L. REYNOLDS ERNEST W SWIDER Attesting Officer Ac ting Commissioner of Patents 

